代码

#include <iostream>
#include <vector>
#include <climits>

// Helper function for counting sort
void countingSort(unsigned *a, int n, int exp) {
    std::vector<unsigned> output(n);
    std::vector<int> count(256, 0);

    // Count occurrences of each byte (0-255) at position 'exp'
    for (int i = 0; i < n; i++) {
        count[(a[i] >> exp) & 0xFF]++;
    }

    // Accumulate count
    for (int i = 1; i < 256; i++) {
        count[i] += count[i - 1];
    }

    // Build the output array
    for (int i = n - 1; i >= 0; i--) {
        output[count[(a[i] >> exp) & 0xFF] - 1] = a[i];
        count[(a[i] >> exp) & 0xFF]--;
    }

    // Copy the output array to the original array
    for (int i = 0; i < n; i++) {
        a[i] = output[i];
    }
}

// Radix Sort function
void sort(unsigned *a, int n) {
    // Perform counting sort for every byte (8 bits)
    for (int exp = 0; exp < 32; exp += 8) {
        countingSort(a, n, exp);
    }
}

评测结果